@nam088/mcp-database-server

MCP (Model Context Protocol) server for multiple database types, designed with a modular architecture for easy extensibility.

📖 Read in Vietnamese: README.vi.md

Features

The server provides the following tools:

• query: Execute SELECT queries and return results
• execute_sql: Execute any SQL command (INSERT, UPDATE, DELETE, CREATE, etc.)
• list_tables: List all tables in the database
• describe_table: Get detailed information about a table's schema

Architecture

The project is split into separate modules:

src/
├── index.ts              # Entry point, initializes adapter based on DB_TYPE
├── server.ts             # MCP server implementation
└── adapters/
    ├── base.ts           # Base adapter interface
    ├── postgres.ts       # PostgreSQL adapter implementation
    ├── mysql.ts          # MySQL adapter implementation
    ├── sqlite.ts         # SQLite adapter implementation
    ├── redis.ts          # Redis adapter implementation
    ├── mongo.ts          # MongoDB adapter implementation
    └── ldap.ts           # LDAP adapter implementation

Database Adapters

Each database has its own adapter implementing the DatabaseAdapter interface:

• PostgresAdapter: PostgreSQL support with 13 SQL tools
• MySQLAdapter: MySQL/MariaDB support with 13 SQL tools
• SQLiteAdapter: SQLite support with 13 SQL tools (using better-sqlite3)
• RedisAdapter: Redis support with 16 Redis tools
• MongoAdapter: MongoDB support with 15 MongoDB tools
• LDAPAdapter: LDAP support with 6 LDAP tools

Installation

1. Install dependencies:

npm install

2. Build the project:

npm run build

Configuration

Environment Variables

• DB_TYPE: Database type (default: postgres)

  • postgres or postgresql: PostgreSQL
  • mysql or mysql2: MySQL/MariaDB
  • sqlite: SQLite
  • redis: Redis
  • mongodb or mongo: MongoDB
  • ldap: LDAP

• READ_ONLY_MODE: Read-only mode (default: true - safer)

  • true or not set: Only allows reads, blocks all write operations (default)
  • false or 0: Allows both read and write (must be set explicitly)

• POSTGRES_CONNECTION_STRING: Connection string for PostgreSQL

• MYSQL_CONNECTION_STRING or MYSQL_URL: Connection string for MySQL

• SQLITE_CONNECTION_STRING or SQLITE_URL: Connection string for SQLite (file path)

• REDIS_CONNECTION_STRING or REDIS_URL: Connection string for Redis

• MONGODB_CONNECTION_STRING or MONGODB_URL: Connection string for MongoDB

• LDAP_CONNECTION_STRING or LDAP_URL: Connection string for LDAP

• LDAP_BIND_DN: Bind DN for LDAP authentication (optional)

• LDAP_BIND_PASSWORD: Bind password for LDAP authentication (optional)

• DATABASE_URL: Connection string (fallback for PostgreSQL, MySQL, or SQLite)

Examples:

# PostgreSQL with read-only mode (default, no need to set READ_ONLY_MODE)
export DB_TYPE="postgres"
export POSTGRES_CONNECTION_STRING="postgresql://user:password@localhost:5432/mydb"
# READ_ONLY_MODE defaults to true

# Redis with write access (must be set explicitly)
export DB_TYPE="redis"
export REDIS_CONNECTION_STRING="redis://localhost:6379"
export READ_ONLY_MODE="false"

# MySQL with read-only mode (default)
export DB_TYPE="mysql"
export MYSQL_CONNECTION_STRING="mysql://user:password@localhost:3306/mydb"
# READ_ONLY_MODE defaults to true

# SQLite with read-only mode (default)
export DB_TYPE="sqlite"
export SQLITE_CONNECTION_STRING="sqlite://./database.sqlite"
# READ_ONLY_MODE defaults to true

# MongoDB with read-only mode (default)
export DB_TYPE="mongodb"
export MONGODB_CONNECTION_STRING="mongodb://localhost:27017/mydb"
# READ_ONLY_MODE defaults to true

Usage

Using npx (Recommended)

After publishing, you can run the server directly with npx without installing:

npx @nam088/mcp-database-server

Local Development

Run the server locally:

npm start

Or run in development mode with watch:

npm run dev

MCP Client Configuration

Add the server to your MCP client configuration (e.g., Claude Desktop). You can use either npx (recommended) or node with a local path.

Using npx (Recommended)

The easiest way is to use npx, which will automatically download and run the package:

{
  "mcpServers": {
    "postgres-readonly": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "postgres",
        "POSTGRES_CONNECTION_STRING": "postgresql://user:password@localhost:5432/mydb"
      }
    }
  }
}

Note: The -y flag automatically accepts package installation if not already present.

Using Local Installation

If you prefer to install locally or use a specific path:

{
  "mcpServers": {
    "postgres-readonly": {
      "command": "node",
      "args": ["/path/to/database-server/dist/index.js"],
      "env": {
        "DB_TYPE": "postgres",
        "POSTGRES_CONNECTION_STRING": "postgresql://user:password@localhost:5432/mydb"
      }
    }
  }
}

PostgreSQL

Read-Only Mode (Default) with npx

No need to set READ_ONLY_MODE as this is the default:

{
  "mcpServers": {
    "postgres-readonly": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "postgres",
        "POSTGRES_CONNECTION_STRING": "postgresql://user:password@localhost:5432/mydb"
      }
    }
  }
}

Read-Write Mode with npx

Note: You must explicitly set READ_ONLY_MODE to "false" to allow write operations.

{
  "mcpServers": {
    "postgres": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "postgres",
        "POSTGRES_CONNECTION_STRING": "postgresql://user:password@localhost:5432/mydb",
        "READ_ONLY_MODE": "false"
      }
    }
  }
}

With DATABASE_URL using npx

{
  "mcpServers": {
    "postgres": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "postgres",
        "DATABASE_URL": "postgresql://user:password@localhost:5432/mydb"
      }
    }
  }
}

Redis

Read-Only Mode with npx

{
  "mcpServers": {
    "redis-readonly": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "redis",
        "REDIS_CONNECTION_STRING": "redis://localhost:6379",
        "READ_ONLY_MODE": "true"
      }
    }
  }
}

Read-Write Mode with npx

Note: You must explicitly set READ_ONLY_MODE to "false" to allow write operations.

{
  "mcpServers": {
    "redis": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "redis",
        "REDIS_CONNECTION_STRING": "redis://localhost:6379",
        "READ_ONLY_MODE": "false"
      }
    }
  }
}

With REDIS_URL and password using npx

{
  "mcpServers": {
    "redis": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "redis",
        "REDIS_URL": "redis://:password@localhost:6379/0"
      }
    }
  }
}

Redis with SSL/TLS using npx

{
  "mcpServers": {
    "redis": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "redis",
        "REDIS_CONNECTION_STRING": "rediss://user:password@redis.example.com:6380"
      }
    }
  }
}

MongoDB

Read-Only Mode with npx

{
  "mcpServers": {
    "mongodb-readonly": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "mongodb",
        "MONGODB_CONNECTION_STRING": "mongodb://localhost:27017/mydb",
        "READ_ONLY_MODE": "true"
      }
    }
  }
}

Read-Write Mode with npx

Note: You must explicitly set READ_ONLY_MODE to "false" to allow write operations.

{
  "mcpServers": {
    "mongodb": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "mongodb",
        "MONGODB_CONNECTION_STRING": "mongodb://localhost:27017/mydb",
        "READ_ONLY_MODE": "false"
      }
    }
  }
}

MongoDB with authentication using npx

{
  "mcpServers": {
    "mongodb": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "mongodb",
        "MONGODB_CONNECTION_STRING": "mongodb://username:password@localhost:27017/mydb?authSource=admin"
      }
    }
  }
}

MongoDB with replica set using npx

{
  "mcpServers": {
    "mongodb": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "mongodb",
        "MONGODB_CONNECTION_STRING": "mongodb://host1:27017,host2:27017,host3:27017/mydb?replicaSet=myReplicaSet"
      }
    }
  }
}

MongoDB Atlas (Cloud) using npx

{
  "mcpServers": {
    "mongodb-atlas": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "mongodb",
        "MONGODB_CONNECTION_STRING": "mongodb+srv://username:password@cluster.mongodb.net/mydb?retryWrites=true&w=majority"
      }
    }
  }
}

MySQL

Read-Only Mode (Default) with npx

No need to set READ_ONLY_MODE as this is the default:

{
  "mcpServers": {
    "mysql-readonly": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "mysql",
        "MYSQL_CONNECTION_STRING": "mysql://user:password@localhost:3306/mydb"
      }
    }
  }
}

Read-Write Mode with npx

Note: You must explicitly set READ_ONLY_MODE to "false" to allow write operations.

{
  "mcpServers": {
    "mysql": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "mysql",
        "MYSQL_CONNECTION_STRING": "mysql://user:password@localhost:3306/mydb",
        "READ_ONLY_MODE": "false"
      }
    }
  }
}

MySQL with DATABASE_URL using npx

{
  "mcpServers": {
    "mysql": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "mysql",
        "DATABASE_URL": "mysql://user:password@localhost:3306/mydb"
      }
    }
  }
}

SQLite

Read-Only Mode (Default) with npx

No need to set READ_ONLY_MODE as this is the default:

{
  "mcpServers": {
    "sqlite-readonly": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "sqlite",
        "SQLITE_CONNECTION_STRING": "sqlite://./database.sqlite"
      }
    }
  }
}

Read-Write Mode with npx

Note: You must explicitly set READ_ONLY_MODE to "false" to allow write operations.

{
  "mcpServers": {
    "sqlite": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "sqlite",
        "SQLITE_CONNECTION_STRING": "sqlite://./database.sqlite",
        "READ_ONLY_MODE": "false"
      }
    }
  }
}

SQLite with absolute path using npx

{
  "mcpServers": {
    "sqlite": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "sqlite",
        "SQLITE_CONNECTION_STRING": "/path/to/database.sqlite"
      }
    }
  }
}

LDAP

Note: The project uses ldapts instead of ldapjs (which has been decommissioned) to ensure sustainability and better support.

Read-Only Mode (Default) with npx

No need to set READ_ONLY_MODE as this is the default:

{
  "mcpServers": {
    "ldap-readonly": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "ldap",
        "LDAP_CONNECTION_STRING": "ldap://localhost:389"
      }
    }
  }
}

Read-Write Mode with npx

Note: You must explicitly set READ_ONLY_MODE to "false" to allow write operations.

{
  "mcpServers": {
    "ldap": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "ldap",
        "LDAP_CONNECTION_STRING": "ldap://localhost:389",
        "READ_ONLY_MODE": "false"
      }
    }
  }
}

LDAP with authentication using npx

{
  "mcpServers": {
    "ldap": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "ldap",
        "LDAP_CONNECTION_STRING": "ldap://localhost:389",
        "LDAP_BIND_DN": "cn=admin,dc=example,dc=com",
        "LDAP_BIND_PASSWORD": "password123"
      }
    }
  }
}

LDAP with LDAPS (SSL/TLS) using npx

{
  "mcpServers": {
    "ldap": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "ldap",
        "LDAP_CONNECTION_STRING": "ldaps://ldap.example.com:636"
      }
    }
  }
}

Active Directory (Microsoft) using npx

{
  "mcpServers": {
    "ldap-ad": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "ldap",
        "LDAP_CONNECTION_STRING": "ldap://ad.example.com:389",
        "LDAP_BIND_DN": "CN=Service Account,CN=Users,DC=example,DC=com",
        "LDAP_BIND_PASSWORD": "password123"
      }
    }
  }
}

Configuring Multiple Databases with npx

You can configure multiple databases in the same MCP client:

{
  "mcpServers": {
    "postgres": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "postgres",
        "POSTGRES_CONNECTION_STRING": "postgresql://user:password@localhost:5432/mydb",
        "READ_ONLY_MODE": "true"
      }
    },
    "redis": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "redis",
        "REDIS_CONNECTION_STRING": "redis://localhost:6379",
        "READ_ONLY_MODE": "false"
      }
    },
    "mysql": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "mysql",
        "MYSQL_CONNECTION_STRING": "mysql://user:password@localhost:3306/mydb"
      }
    },
    "sqlite": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "sqlite",
        "SQLITE_CONNECTION_STRING": "sqlite://./database.sqlite"
      }
    },
    "mongodb": {
      "command": "npx",
      "args": ["-y", "@nam088/mcp-database-server"],
      "env": {
        "DB_TYPE": "mongodb",
        "MONGODB_CONNECTION_STRING": "mongodb://localhost:27017/mydb"
      }
    }
  }
}

Read-Only Mode

⚠️ By default, the server runs in read-only mode to protect data from accidental deletion or modification. When READ_ONLY_MODE is true or not set (default), the server will block all write operations:

PostgreSQL, MySQL, SQLite:

• ✅ Allowed: query (SELECT)
• ❌ Blocked: execute_sql (INSERT, UPDATE, DELETE, CREATE, etc.)

Redis:

• ✅ Allowed: redis_get, redis_keys, redis_exists, redis_ttl, redis_type, redis_dbsize, redis_info, redis_hget, redis_hgetall, redis_lrange, redis_smembers, redis_zrange
• ❌ Blocked: redis_set, redis_del, redis_expire, redis_hset

MongoDB:

• ✅ Allowed: mongo_find, mongo_find_one, mongo_count, mongo_aggregate, mongo_list_collections, mongo_get_collection_stats, mongo_get_indexes, mongo_get_database_stats
• ❌ Blocked: mongo_insert_one, mongo_insert_many, mongo_update_one, mongo_update_many, mongo_delete_one, mongo_delete_many, mongo_create_index

LDAP:

• ✅ Allowed: ldap_search, ldap_authenticate, ldap_compare
• ❌ Blocked: ldap_add, ldap_modify, ldap_delete

When attempting to execute a write operation in read-only mode, the server will return an error:

Error: Server is running in read-only mode. Write operations are disabled.

Adding a New Database Adapter

To add support for a new database:

1. Create a new adapter file in src/adapters/ (e.g., mysql.ts)
2. Implement the DatabaseAdapter interface from base.ts
3. Add a new case in src/index.ts to initialize the adapter

Example:

// src/adapters/mysql.ts
import { DatabaseAdapter, QueryResult, ExecuteResult, TableSchema } from "./base.js";

export class MySQLAdapter implements DatabaseAdapter {
  // Implement methods from DatabaseAdapter
  async query(sql: string): Promise<QueryResult> { ... }
  async execute(sql: string, params?: any[]): Promise<ExecuteResult> { ... }
  async listTables(schema?: string): Promise<string[]> { ... }
  async describeTable(table: string, schema?: string): Promise<TableSchema> { ... }
}

Then add to src/index.ts:

case "mysql":
  return new MySQLAdapter(connectionString);

Tools

query

Execute a SELECT query:

{
  "name": "query",
  "arguments": {
    "sql": "SELECT * FROM users LIMIT 10"
  }
}

execute_sql

Execute a SQL command:

{
  "name": "execute_sql",
  "arguments": {
    "sql": "INSERT INTO users (name, email) VALUES ('John', 'john@example.com')"
  }
}

list_tables

List tables:

{
  "name": "list_tables",
  "arguments": {
    "schema": "public"
  }
}

describe_table

Describe table schema:

{
  "name": "describe_table",
  "arguments": {
    "table": "users",
    "schema": "public"
  }
}

License

MIT